Pulldown device



` Jan. 29, 1946. c, D, BEETH PULL-Down DEVICE Filed Feb. 1, 1943 2 Sheets-Sheet 1 ...EEE

Jan. 29, 194e. Q BEETH 2,393,603

PULL-DOWN DEVI CE Filed Feb.- 1, 1943 2 sheets-sheet 2 IIA .A TT( EN Patented Jan. 29, 1946 UNITED STATES PATENT OFFICE 2,393,603 PULLnowN nEvrcE Clarence Donald Beeth, Jacksboro, Tex. Application February 4l, 1943, Serial No. 474,259 3 Claims. (Cl. Z55-22) My invention relates to improvements in pulldown or force feed devices for rotary well drilling equipment.

When drilling a well with rotary equipment, the string of drill pipe is suspended from the lower end of a vertical kelly or shaft rotatably and slidably mounted in a suitable supporting structure at the surface. 'I'he kelly shaft is driven by a motor to rotate the drill pipe. Until the well becomes deep enough so that the kelly and drill pipe have suillcient weight tb give a proper cutting action. and even thereafter when drilling hard strata, mechanism must be provided to force the shaft and drill pipe downwardly into the well bore. This mechanism is usually referred to as a pull-down or force feed" device.

In the past it has been conventional practice` to attach the cable of a power winch to the kelly and bring downward pressure upon the kelly and drill pipe in this manner. This is likely to bend or warp the expensive kelly and besides is a dangerous practice. If the cable breaks it is very likely to whip about injuring workmen and destroying or damaging equipment,

It is also conventional practice to apply downward pressure on the drill pipe by means of a hydraulic unit chucked to the kelly. A hydraulic unit however has a limited vertical movement usually of from one to four feet so the chuck must be loosened after each down stroke and readjusted to maintain continuous downward pressure on the pipe. This is a tedious, time consuming, expensive and arduous task. Furthermore, the drilling mechanism must be stopped while rechucking.

According to the instant invention, a pull-down device carried by the hydraulic unit replaces the chuck and is associated with the kelly in such a way that rechucking is eliminated. The pulldown automatically attaches to the kelly when the hydraulic goes down, and automatically releases the kelly when the hydraulic rises. When my pull-down is used it is unnecessary to stop the drilling mechanism after each stroke of the hydraulic unit.

In the drawings forming part of this specification, and wherein like numerals are employed to designate like parts throughout the same,

Fig. l is an elevational view showing a hydraulic unit coupled to a kelly shaft by means of a pull-down embodying my invention, (and a conventional chucking device in dotted lines),

Fig. 2 is a top plan view of the pull-down, parts being broken away for clearness of illustration,

Fis'. 3 is a, vertical sectional view taken on the line 3--3 of Fig. 2, and showing the jaws of the pull-down released from the kelly,

Fig. 4 is a transverse sectional view taken on the line 1 4 of Fig. 3,

Fig. 5 is a side elevation of the pull-down, parts being broken away to show the jaws engaging the kelly, f

Fig. 6 is a fragmentary vertical sectional view taken on the line 6-6 of Fig. 5,

Fig. 7 is a vertical sectional view showing a modified pull-down,

Fig. 8 is a vertical sectional view showing another modication of the pull-down, and

Fig. 9 is a vertical view showing still another modification of the pull-down.

In the drawings, wherein for the purpose of illustration is shown a preferred embodiment of my invention, the numeral I0 designates a, conventional kelly shaft. The kelly, extending vertically from the well and having the string of drilling rods (not shown) attached to its lower end, is rotated in the conventional manner by means of the quill shaft Il and motor It. The quill shaft Il is sleeved on the kelly and. rotatably driven by the motor. The quill is slidable on the kelly but rotatably locked therewith by means of keys I3 lying in registering longitudinal grooves Illa and Ila in the kelly I0 and drive bushing Id. It is to be understood that l my device can be associated with other types of kellys such as those of square or hexagonal cross section. When these latter types are employed, the key and groove connection will not be neoessary. Lugs Mb and set screws I5 connect the drive bushing I4 with a drive sleeve I 6. `the latter threaded on the upper end of quill I l. Thus, motor I2 rotates quill II, drive sleeve I6 and drive bushing Ill, which in turn drives the kelly Ill and drill pipe (not shown). As the well bore deepens the kelly moves downwardly through the quill.

The quill is moved up and down by means of the hydraulic unit Il which includes vertically reciprocable piston rods I8 at opposite sides of the kelly. A yoke I9 fastened to the piston rods I8 has a collar I 9a in which the upper end of the quill Il is journaled. A ange 20 extending radially from the quill between bearings 2| and 22 compels the quill to move vertically with the yoke but permits the quill to rotate freely within the yoke collar.

Heretofore, downward pressure has been brought to bear on the kelly by fastening the quill II directly to the kelly In during the downstroke of the hydraulic. This was done by means of a chuck 2l shown in dotted. lines at the lower endofthequillinll'lg. 1. Thepractlcehasbeen to fasten the chuck 23 to the kelly by means of set screws 25a. Consequently, it was necessary to loosen the set screws and rechuck after each down stroke of the hydraulic I1. The instant invention eliminates the chuck 23 and provides a pull-down by means of which the hydraulic Il is automatically coupled to the kelly I on its downstroke and automatically released from the kelly on its upstroke.

This pull-down for automatically coupling the hydraulic to the kelly is housed within a case 24. Case 24 is bolted to angle brackets I4a which project radially from the drive bushing I4. Consequently, the pull-down is reciprocally and rotatably movable with the quill II. Jaws 25 are movable to engage and release the kelly I5 by radially arranged toggle links 26. 'I'he toggle links have their outer ends journaled in bearing plates 21 bolted within case 24. Tension springs 28 urge the toggle links 26 upwardly and the jaws into engagement with the kelly, as shown in Fig. 5. Guide pins 29 extending through elongated slots in toggle links 26 and have stops 29' adjustably threaded thereon to limit the upward movement of the toggle links under action of the springs and to hold the toggle links in position to properly present the jaws to the kelly.

With the jaws in the position shown in Fig. 5, the hydraulic is positively coupled to the kelly Ill. As the hydraulic moves downwardly, it will exert a downward pressure on the kelly and drill pipe through the medium of yoke I 9, drive sleeve I6, drive bushing I5, case 24, toggle links 26 and jaws 25. Because of the inclined position of the toggle links, the gripping action of the jaws increases as the hydraulic pressure increases. During operation of the hydraul I1, motor I2 continuously rotates quill I I and its associated mechanism above described. Consequently, quill II rotates kelly Ill-and the attached string of drill rods.

When the hydraulic reaches the bottom of its stroke, its direction of travel is reversed and as it rises it lifts quill I l, drive sleeve I6, drive bushing I5 and the pull-down device with it. As the hydraulic moves upwardly, toggle links 25 swing the jaws 25 downwardly, thereby releasing the hydraulic from the kelly. When the hydraulic reaches the upper limit of its stroke, it again reverses its direction of travel when springs 28 cause the-jaws 25 to engage the kelly I0 and again couple the hydraulic I1 with the kelly.

Occasionally, as when changing drill pipe or spudding, it is desirable to hold the jaws 25 away from kelly Ill for a considerable length of time and for this purpose a special releasing mechanism is provided. This mechanism consists of a circular plate 30 located above case 24 which is raised and lowered by links 3|. A manually operated release control handle 32 is attached to bifurcation 33. Member- 33 is pivoted at 34 near its ends to brackets 33a and at 35 to lifting links 3l. When the release control handle is in the raised position, shown by the full lines in Figs. 5 and 6, plate 30 is raised, permitting jaws 25 to engage the kelly I0. When the release control handle 32 is in a lowered position, shown by the dotted lines in Fig. 6, plate 30 is lowered to the position shown in Fig. 3, so that bearing 35 on the under side of the plate presses against jaws 25, urging them down and away from the kelly. In this last position of the release control handle escasos 32,thehydraulieisreleasedfromthekellyimtil suchtimeastherelease controlhandleisraised.

In the modified form of the invention shown in Fig. 'I the jaws 25 have upwardly tapered rear surfaces l1 while the surrounding 'case 24 has coacting bearing surfaces 38 in spaced parallel relation therewith. The jaws are `supported on springs 39 to normally hold an anti-friction means such as roller bearings 4II in the space between the jaws and bearing surfaces.

When case 24 is moved downwardly by the hydraulic, jaws 25 will be brought into binding engagement with the kelly I5. The force exerted against the jaws 25 increases as the hydraulic force increases. As soon as travel of the hydraulic is reversed, jaws 25 will be released from the kelly.

The modication shown in Fig. 8 is identical with that shown in Fig. 'I except that the bearing surfaces are replaced by rollers 4I journaled between brackets 42 behind the respective jaws 25.

As case 24 is movedV downwardly by the hydraulic, when this modification is employed, cam rollers 4| ride along the inclined surfaces 31 of the jaws to move the jaws into .binding engagement with the kelly. When the hydraulic rises, rollers 4I ride upwardly on the rear surfaces 31 of the jaws, permitting the jaws to release the kelly I0.

In the modification shown in Fig. 9, jaws 25 have vertical rear surfaces 43 and are supported on coil springs 44. Cam rollers 45 mounted for eccentric movement between brackets 46 behind the respective jaws, cause the jaws to automatically grip and release the kelly during reciprocation of the hydraulic.

Springs 41 create sulcient initial friction between cams 45 'and the jaws 25 and between the jaws 25 and kelly I5 to cause the cams to rotate and urge the jaws into binding engagement with the kelly IllI with actuation of the hydraulic.

It is to beunderstood that the forms of the invention herein shown and described are to be taken as preferred examples of the same, and that various changes in the size, shape and arrangement of parts may be resorted to without departing from the spirit of my invention or the scope of the appended claims.

Having thus described my invention, I claim:

1. In rotary well drilling equipment employing a kelly fed by a hydraulic pull-down unit. the improvement comprising a .rotatable case movable with the hydraulic and surrounding the kelly, jaws in the case in proximity to the kelly, radially arranged toggle links having their inner ends pivoted to respective jaws, fixed bearings pivotally supporting the outer ends of the toggle links higher than the inner ends thereof, yielda-ble means normally urging the inner ends of the toggle links upwardly to move the jaws into binding engagement with the kelly, the inclination of said toggle links downwardly from the bearings to the jaws permitting said yieldable means to automatically move the jaws into binding engagement with the kelly when the hydraulic is lowered and out of binding engagement with the kelly when the hydraulic is raised and stop means located in the path of the toggle links for limiting movement of the toggle links under action of the yleldable means.

2. In rotary well drilling equipment employing a kelly fed by a hydraulic pull-down unit, the improvement comprising a rotatable case movable with the hydraulic and surrounding the kelly, jaws in the case in proximity to the kelly,

radially arranged toggle links having their inner ends pivoted to respective jaws, fixed bearings pivotally supporting the outer ends of the links higher than the inner ends thereof, springs normally urging the jaws and toggle links about the bearing pivots to move the jaws into engagement with the kelly, toggle link guides fixed to the case, stop means on the guides adapted to be engaged by the toggle links to limit movement of the jaws under action of the springs, and a jaw release mechanism carried by the hydraulic including a plate mounted above said case, means for raising and lowering the plate relative to the case, and a bearing on the plate adapted to press against the jaws and hold them away from the kelly when the plate is lowered and to release the jaws when the plate is raised permitting said springs to move the jaws automatically into engagement with the kelly.

3. In rotary well drilling equipment employing a kelly fed by a hydraulic pull-down unit, the improvement comprising a rotatable case movable with the hydraulic and surrounding the kelly, jaws in the case in proximity to the kelly,

radially arranged toggle links having their inner ends pivoted to respective jaws, fixed bearings pivotally supporting the outer ends of the links higher than the inner ends thereof, springs normally urging the jaws upwardly pivoting the toggle links in the bearing pivots whereby to move said jaws into engagement with the kelly, stop means located in the case in the path of the toggle links for restricting movement of the toggle links under action of said springs, and a jaw release mechanism including a plate mounted above the case, arms extending from the plate, brackets on the hydraulic unit, and a handle having a bifurcation, spaced pivots connecting the bifurcation to said brackets and said arms whereby pivotal movement of the handle raises and lowers the plate, and a bearing on the plate adapted to press against the jaws and hold them .away from the kelly when the plate is lowered and to release the jaws when the plate is raised permitting said springs to move the jaws into engagement with the kelly.

CLARENCE DONALD BEETH. 

